Electric door-alarm.



ELECTRIC DOOR ALARM.

APPLICATION FILED JULY 31, 1908.

1,012,590. Patented Dec.26,1911.

COLUMBIA PLANDOIAIii CO.,WASH|NOTDN, n. c.

UNITED STATES PATENT OFFICE.

CHARLES F. BOBO, OF BROOKLYN, NEW YORK.

ELECTRIC DOOR-ALARM.

lb all whom it may concern:

Be it known that I, CHARLES F. BOBO, a citizen of the United States, residing at Brooklyn, county of Kings, and State of New York, have invented certain new and useful Improvements in Electric Door- Alarms, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to a portable automatic electric door alarm; and aims to provide an alarm device which may be readily attached to and detached from the door and the controlling mechanism of which is so constructed that the alarm maybe set so as not to operate, or may be adjusted by a simple operation when the door is open so that on the door being closed the controlling mechanism will be automatically set to cause the alarm to be soundedwhen the door is again opened.

The invention aims further to provide an alarm device of this character which cannot be tampered with or put out of operation by a person outside of the room without causing the alarm to be sounded.

As a full understanding of the invention can best be given by a detailed description of a preferred construction embodying the various features of the invention, such a description will now be given in connection with the accompanying drawings showing such a preferred construction and a modification thereof.

In said drawings, Figure 1 shows the device in front elevation attached to a door. Fig. 2 is a section on the line 22 of Fig. 1. Fig. 3 is a top view of the device with a part of the battery casing broken away. Fig.4 is a partial front view showing the controlling devices, but showing them in a different position from that in which they are shown in Fig. 1. Fig. 5 is a detail end view looking in the direction of the arrow 5 on Fig. 1 and showing the circuit closing spring in the position it takes when the door is closed. Fig. 6 is a similar view showing the position of the circuit closing spring in its circuit closing position. Fig. 7 is a detail front view showing a modified form of contact device. Fig. 8 is a plan view of the device shown in Fig. 7. Fig. 9 is a detail view of a modification hereinafter described.

Referring to the drawings :10 represents an electrically operated alarm sounding de- Specification of Letters Patent.

Application filed July 31, 1908.

Patented Dec. 26, 1911.

Serial No. 446,225.

vice which is preferably an ordinary alarm bell as shown. This electric bell is mounted on a box or casing 11 which serves for holding a battery 12, and which is adapted to be secured to the door 13 in position to cause the circuit controlling means to be operated .on the closing and opening of the door as hereinafter described. An ordinary dry battery is preferably used, and the box or casing 11 is made so that it may be opened to permit of the removal or insertion of the battery, so that when a battery is used up a new one may be substituted. One terminal 15 of the bell magnet winding is connected with a contact 16, shown in dotted lines in Fig. 1, in position to engage one of the battery terminals 17, and the other battery terminal 17 engages a contact 18 which is connected by a conducting strip 19 with a circuit closer 20 through which circuit may be completed to the other terminal of the bell magnet winding 21.

The battery box or casing may be secured to the door in any suitable manner. Preferably, however, the box is provided with metal strips 23 having projecting ends 24 adapted to rest on the edge, preferably the top edge, of the doorand provided with downwardly bent points 25 adapted to be driven into the door as shown in the drawings so as to hold the box securely in place on the door. The box may thus be easily attached to the door and readily removed whenever desired. The box is preferably formed with a sliding back or cover 26, and the metallic strips 23 are preferably secured to such back or cover so that the box and the alarm mechanism carried by it may be readily removed simply by sliding the box from the back or cover which remains secured to the door. A new battery may thus be easily inserted in the box or the box taken down for repair or adjustment of the alarm mechanism without disturbing the means for securing the box to the door. The back or cover 26 of the box might, of course, be secured to the door in any other suitable manner.

The circuit closer 20 is preferably formed by a flat spring, as shown, the lower end of which is secured to the box and electrically connected with the conducting strip 19 on the inside of the box, and which tends to move toward the box into engagement with a contact piece 30 electrically connected with the bell terminal 21 to complete the bell circuit and cause the bell to ring. The battery box is intended to be secured to the door with its upper side substantially in line with the top edge of the door, and a push piece or holding device 31 which is connected with the contact spring 20 is mounted to slide on the top of the battery box. The inner end 32 of the push piece or holding device normally projects over the edge of the door as shown in Fig. 6, sh that when the door is closed the end 32 will come into engagement with the door frame 33 and the push piece will be forced outward to push the circuit closing spring 20 away from the contact piece 30, as shown in Fig. 5. This push piece or holding device is preferably formed by a part of the spring which forms the circuit closing spring 20, bent to ex tend over the side of the box 11 and having its inner end bent upward and backward substantially in the form shown in Figs. 2, 5 and 6 to form the door frame engaging part 32.

If only the parts so far described were provided, the bell circuit would be closed and the alarm sounded every time the door was opened. To avoid this, means are provided for setting the alarm device so as to cause the bell to ring or not when the door is opened as desired. For this purpose, a setting device is provided formed by a pivoted stop 35 which is adapted to be turned so as to throw one end into position to prevent the circuit closing spring 20 from moving into engagement with the contact piece 30, and having an operating arm or handle 36 connected with its other end, which handle may be of sufficient length to extend down within easy reach. By pulling down 011 the handle 36, the stop piece 35 may be swung to the position shown in Fig. 4, leaving the circuit closing spring 20 free to move into engagement with the contact piece 30, and by moving the handle to throw its upper end slightly to the left and then push ing upward on it the stop piece 35 may be swung into its operative position with one end extending beneath the circuit closing spring 20 in position to prevent the circuit closing spring from moving into engagement with the contact piece 30. (See Figs. 1, 2 and 5). The stop 35 tends to take the position shown in Fig. 4, the weight of the handle'36 in the construction shown being sufficient to move the stop from its operative position, shown in Fig. 1 and in dotted lines in Fig. 4, to its inoperative position, shown in full lines in Fig. 4, if its movement is not restrained. Vhen the door is open, however, the circuit closing spring 20 will bear against the end of the stop arm, if the latter is in its operative position, with sufficient force to hold it in such position. When the door is closed and the circuit closing spring moved away from the end of the the drawings, and so that the handle will be frictionally held when beneath the left hand portion of the guide plate. This result is preferably secured by forming the guide plate of a strip of sheet metal and punching an inwardly extending lug 38 in it adapted to bear against the handle 36, which is also preferably formed of a flat metal strip and provided with a hole 39 in position to register with the lug 33 when the stop 35 is in its operative position and the handle moved over to the left in the guide 37. hen the stop 35 and handle 36 are in the position shown in Fig. 1, therefore, the circuit closing spring 20 is prevented from closing the bell circuit, but if the stop and handle are in the position shown by full lines in Fig. 4 when the door is closed, then when the door is open the circuit closing spring 20 will move into engagement with the contact piece 30, as shown in Fig. 6, clos ing the circuit to the bell and causing the alarm to be sounded. Also, if, when the door is open, the handle 36 is moved over to the position shown by dotted lines in Fig. 4, the stop 35 will then be held in its operative position merely by the pressure of the circuit closing spring 20 thereon until the door is closed; and when the door is closed and the circuit closing spring moved to the position shown in Figs. 2 and 5, the stop will be released and the stop and handle 36 will move to the position shown by full lines in Fig. 4, the alarm mechanism thus being automatically set so that when the door is opened the circuit closing spring will be free to move into engagement with the contact piece 30 to close the bell circuit to cause the alarm to be sounded. With this construction, therefore, if a person wishes to go out of the room and leave the alarm set to operate, all that is necessary to be done is to throw the handle 36 over to the position shown by dotted lines in Fig. 4, and when the door is closed the stop will move out of operative position and the alarm mechanism will be set to ring if the door is opened.

In order to prevent the alarm mechanism from being put out of operation by any one tampering with the push piece or holding device 31 from the outside, the circuit closing spring 20 and contact piece 30 are formed so that if the circuit closing spring is pushed too far back or to either side from its normal position the circuit will be closed and the alarm sounded. For this purpose in the preferred construction, the contact piece 80 is formed of a metallic strip bent so as to extend entirely around the circuit closing spring 20, and the circuit closing spring is preferably mounted on the battery box so that while normally held against edgewise movement it will yet be free to move edgewise'into engagement with the contact piece 30 if sufficient pressure is exerted on it or on the push piece 31. For this purpose, the circuit closing spring is shown as secured to the battery box by means of two screws 40 and 41, the latter of which extends through a short cross slot in the spring and is screwed down sufficiently hard to hold the spring in against edgewise movement under normal conditions.

Instead of the arrangement shown in Figs. 1 to 6 for causing the alarm .to be sounded if the circuit closing spring is thrown out of its normal position, other suitable means might be provided for this purpose. For example, instead of providing a contact piece 30 which extends around and incloses the circuit closing spring, a contact piece of the form shown in Figs. and 8, might be provided having a spur or projection l2 adapted to extend through an opening 43 in the circuit closing spring and having a bent over end 44. Obviously this construction insures the closing of the bell circuit if the circuit closing spring is pushed too far outward or is moved edgewise slightly in either direction from normal position.

In the case of some doors, the relative positions of the edge of the door and the edge of the door frame when the door is closed differs from that in the case of other doors. To adapt the alarm device to doors differing in this particular the push piece or holding device 31 is preferably made adjustable, as by forming the same of two parts relatively adjustable lengthwise and secured by means of a nut 50, as shown in Fig. 9.

It will be understood that the invention is not to be limited to the exact construction and arrangements of parts as shown, but that it includes changes and modifications thereof within the claims.

lVhat is claimed is:

1. In an electric door alarm, the combination of an electrically operated alarm device, a circuit closer in the alarm circuit tending to move into circuit closing position, a stop for preventing the circuit closer from moving into circuit closing position and adapted to be held in its operative position by the circuit closer, and holding means for moving the circuit closer to release the stop when the door is closed and for holding the circuit closer out of operative position while the door is closed, whereby when the door is opened thecircuit closer will be free to moveinto circuit closing position to cause the alarm device to operate.

2. In an electric door alarm, the combination of an electrically operated alarm device, a circuit closer in the alarm circuit tending to move into circuit closing position, setting means for preventing the closing of the alarm circuit, and means for holding the circuit closer out of operative position when the door is closed and for causing the setting means to permit the alarm device to be closed when the holding means is released by the opening of the door.

3. In an electric door alarm, the combination of an electrically operated alarm device, a circuit closer in the alarm circuit tending to move into circuit closing position, a setting device for preventing the sounding of the alarm, and means for holding the circuit closer out of operative position when the door is closed and for causing the setting device to move out of operative position to permit the alarm device to be operated by the closing of the alarm circuit when said means is released by the opening of the door.

I. In an electric door alarm, the combina- 7 tion of an electrically operated alarm device, a circuit closer in the alarm circuit tending to move into circuit closing position, a setting device for preventing the sounding of the alarm, means for holding the circuit closer out of operative position when the door is closed and for causing the setting device to move out of operative position to permit the alarm device to be operated by the closing of the alarm circuit when said means is released by the opening of the door, and locking means for preventing the setting device from being moved out of open ative position through the operation of said first mentioned means.

5. In an electric door alarm, the combination of an electrically operated alarm device, a spring circuit closer tending to move into position to close the circuit to the alarm device, a stop for preventing the circuit closer from moving into position to close the circuit and adapted to be held in operative position by the circuit closer and to move out of operative position when released by the circuit closer, and a holding device connected with the circuit closer and adapted to be moved by engagement with the door frame to release the stop when the door is closed and to hold the circuit closer out of operative position until the door is opened.

6. In an electric door alarm, the combination of an electrically operated alarm device, a spring circuit closer, tending to move into position to close the circuit to the alarm device, a stop for preventing the circuit closer from moving into position to close the circuit and adapted to be held in operative position by the circuit closer and to move out of operative position when released by the circuit closer, a holding device connected with the circuit closer and adapted to be moved by engagement with the door frame to release the stop when the door is closed and to hold the circuit closer out of operative position until the door is opened, and locking means for preventing the stop moving out of operative position when released by the circuit closer.

7. In an electric door alarm, the combina-' tion of an electrically operated alarm device, a circuit closer tending to move into position to close the alarm circuit, setting means adapted to prevent the closing of the alarm circuit, and means operated by the closing of the door for releasing the setting means and for holding the circuit closer out of operative position while the door is closed and for permitting it to move into operative position upon the opening of the door.

8. In an electric door alarm adapted to be mounted on the door, the combination of an electrically operated alarm device, a circuit closer tending to move into position to close the alarm circuit, a holding device adapted to be moved by engagement with the door frame when the door is closed into position to hold the circuit closer out of operative position and to be released when the door is opened to permit the circuit closer to move into operative position, and a contact device adapted to be engaged by the circuit closer to close the alarm circuit, said contact device and circuit closer being formed so that the circuit closer will engage the contact device when moved in either direction sidewise or toward or from the door.

In testimony whereof, I have hereunto set my hand, in the presence of two subscribing witnesses.

CHARLES F. BOBO.

lVitnesses .A. IVHITE,

P. N. TILDEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

